Publicação
A role of local translation at presynaptic terminals
| Resumo: | Mechanisms of on-site protein production allow rapid subcellular responses to extracellular stimuli. This is especially relevant in polarized cells, such as neurons. During development, neurons extend axons to specific target areas and form an intricate network of connections, fundamental for nervous system function. Both axonal navigation and synapse formation are extremely fast processes that depend on target-derived cues. While local translation is important in regulating many aspects of axonal pathfinding, its role in presynaptic assembly is poorly understood. We established that local translation is very rapidly induced in isolated axons upon contact with synaptogenic adhesive substrates. We were able to detect newly synthesized proteins within 15 minutes of contact and inhibiting protein synthesis interfered with the specific clustering of presynaptic proteins at contact sites. We found that the transcript for the t-SNARE protein SNAP25, required for vesicle exocytosis, localizes to axons and clusters around presynaptic specializations and we were able to directly visualize SNAP25 synthesis at these sites. We further demonstrated that inhibiting axonal SNAP25 synthesis interferes with presynaptic protein clustering and synaptic vesicles release dynamics. This project uncovered a fundamental role for intra-axonal SNAP25 synthesis during synaptic terminal assembly. Furthermore, we have implicated local translation defects in delayed functional consequences, which opens up new possibilities relevant for the study of neurodevelopmental disorders. |
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| Autores principais: | Batista, Andreia Filipa Rodrigues |
| Assunto: | Ciências Médicas::Outras Ciências Médicas |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Mechanisms of on-site protein production allow rapid subcellular responses to extracellular stimuli. This is especially relevant in polarized cells, such as neurons. During development, neurons extend axons to specific target areas and form an intricate network of connections, fundamental for nervous system function. Both axonal navigation and synapse formation are extremely fast processes that depend on target-derived cues. While local translation is important in regulating many aspects of axonal pathfinding, its role in presynaptic assembly is poorly understood. We established that local translation is very rapidly induced in isolated axons upon contact with synaptogenic adhesive substrates. We were able to detect newly synthesized proteins within 15 minutes of contact and inhibiting protein synthesis interfered with the specific clustering of presynaptic proteins at contact sites. We found that the transcript for the t-SNARE protein SNAP25, required for vesicle exocytosis, localizes to axons and clusters around presynaptic specializations and we were able to directly visualize SNAP25 synthesis at these sites. We further demonstrated that inhibiting axonal SNAP25 synthesis interferes with presynaptic protein clustering and synaptic vesicles release dynamics. This project uncovered a fundamental role for intra-axonal SNAP25 synthesis during synaptic terminal assembly. Furthermore, we have implicated local translation defects in delayed functional consequences, which opens up new possibilities relevant for the study of neurodevelopmental disorders. |
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